Mercury intrusion porosimetry

Abstract

The determination of pore size following the technique of mercury intrusion is based on the behavior of “nonwetting” liquids in capillary. A liquid coming in contact with a solid porous material and behaving as a non wetting agent (namely if the contact angle of the liquid with that solid material exceeds 90°) cannot be spontaneously absorbed by the pores of the solid itself, because of surface tension. However, this resistance to penetration can be won by applying an external pressure. Required pressure depends on the pore size. The relation between the pore size and the applied pressure, assuming the pore is cylindrical, is expressed as: